1. Field of the Invention
The present invention relates to a floor structure such as a floor plate bridge structure built on a river or land, a slab structure of respective hierarchies such as a steel frame building and an iron reinforced concrete building, a roadbed structure formed on an upper surface of an underground construction, a roadbed structure laid on a ground surface, or the like.
2. Related Art
Patent Document 1 shows a bridge structure, in which steel beams each consisting of an upper flange, a lower flange and a web are arranged in parallel, an iron reinforcement is arranged and concrete is placed between the adjacent steel stocks, i.e., in a space defined by upper and lower flanges of the adjacent steel beams and the web, and the iron reinforced concrete and the web are tightly connected to each other by a PC steel beam piercing the iron reinforced concrete and the web in the width direction of the bridge.
The above bridge structure is based on such a designing idea that the bridge strength against an active load such as vehicles is borne by an iron reinforced concrete placed between the adjacent steel stocks (i.e., steel beams).
Moreover, the slab structure of the respective hierarchies of the conventional steel frame building is formed by supporting a floor plate by beam members, and the slab structure of the respective hierarchies of the iron reinforced concrete building is normally formed with a monolithically placed concrete. Likewise, the roadbed structure temporarily laid on the upper surface of an underground construction employs a method in which iron plates are supported by beam members, and the construction site where trucks and heavy machines frequently come in and out, typically employs a method in which iron plates are merely laid on a ground surface to form a temporary roadbed.
It should be noted that the “Patent Document 1” mentioned above refers to Official Gazette of Japanese Patent Application Laid-Open No. H08-253912